<template>
	<!-- 规格弹窗 -->
	<su-popup :show="show" round="10" @close="emits('close')">
    <!-- SKU 信息 -->
		<view class="ss-modal-box bg-white ss-flex-col">
			<view class="modal-header ss-flex ss-col-center">
				<view class="header-left ss-m-r-30">
					<image class="sku-image" :src="state.selectedSku.picUrl || goodsInfo.picUrl" mode="aspectFill" />
				</view>
				<view class="header-right ss-flex-col ss-row-between ss-flex-1">
					<view class="goods-title ss-line-2">{{ goodsInfo.name }}</view>
					<view class="header-right-bottom ss-flex ss-col-center ss-row-between">
						<view class="ss-flex">
							<view class="price-text">
								{{ fen2yuan( state.selectedSku.price || goodsInfo.price) }}
							</view>
						</view>
						<view class="stock-text ss-m-l-20">
							{{ formatStock('exact', state.selectedSku.stock || goodsInfo.stock) }}
						</view>
					</view>
				</view>
			</view>

      <!-- 属性选择 -->
			<view class="modal-content ss-flex-1">
				<scroll-view scroll-y="true" class="modal-content-scroll" @touchmove.stop>
					<view class="sku-item ss-m-b-20" v-for="property in propertyList" :key="property.id">
						<view class="label-text ss-m-b-20">{{ property.name }}</view>
						<view class="ss-flex ss-col-center ss-flex-wrap">
							<button class="ss-reset-button spec-btn" v-for="value in property.values" :class="[
                  {
                    'ui-BG-Main-Gradient': state.currentPropertyArray[property.id] === value.id,
                  },
                  {
                    'disabled-btn': value.disabled === true,
                  },
                ]" :key="value.id" :disabled="value.disabled === true" @tap="onSelectSku(property.id, value.id)">
								{{ value.name }}
							</button>
						</view>
					</view>
					<view class="buy-num-box ss-flex ss-col-center ss-row-between ss-m-b-40">
						<view class="label-text">购买数量</view>
						<su-number-box :min="1" :max="state.selectedSku.stock" :step="1"
                           v-model="state.selectedSku.goods_num" @change="onNumberChange($event)" />
					</view>
				</scroll-view>
			</view>

      <!-- 操作区 -->
			<view class="modal-footer border-top">
				<view class="buy-box ss-flex ss-col-center ss-flex ss-col-center ss-row-center">
					<button class="ss-reset-button add-btn ui-Shadow-Main" @tap="onAddCart">加入购物车</button>
					<button class="ss-reset-button buy-btn ui-Shadow-Main" @tap="onBuy">立即购买</button>
				</view>
			</view>
		</view>
	</su-popup>
</template>

<script setup>
	import { computed, reactive, watch } from 'vue';
	import sheep from '@/sheep';
  import { formatStock, convertProductPropertyList, fen2yuan } from '@/sheep/hooks/useGoods';

	const emits = defineEmits(['change', 'addCart', 'buy', 'close']);
	const props = defineProps({
		goodsInfo: {
			type: Object,
			default () {},
		},
		show: {
			type: Boolean,
			default: false,
		}
	});

	const state = reactive({
		selectedSku: {}, // 选中的 SKU
		currentPropertyArray: [], // 当前选中的属性，实际是个 Map。key 是 property 编号，value 是 value 编号
	});

	const propertyList = convertProductPropertyList(props.goodsInfo.skus);

	// SKU 列表
	const skuList = computed(() => {
		let skuPrices = props.goodsInfo.skus;
    for (let price of skuPrices) {
      price.value_id_array = price.properties.map((item) => item.valueId)
    }
		return skuPrices;
	});

	watch(
		() => state.selectedSku,
		(newVal) => {
			emits('change', newVal);
		}, {
			immediate: true, // 立即执行
			deep: true, // 深度监听
		},
	);

  // 输入框改变数量
  function onNumberChange(e) {
    if (e === 0) return;
    if (state.selectedSku.goods_num === e) return;
    state.selectedSku.goods_num = e;
  }

  // 加入购物车
	function onAddCart() {
		if (state.selectedSku.id <= 0) {
      sheep.$helper.toast('请选择规格');
      return;
		}
    if (state.selectedSku.stock <= 0) {
      sheep.$helper.toast('库存不足');
      return;
    }

    emits('addCart', state.selectedSku);
	}

  // 立即购买
	function onBuy() {
    if (state.selectedSku.id <= 0) {
      sheep.$helper.toast('请选择规格');
      return;
    }
    if (state.selectedSku.stock <= 0) {
      sheep.$helper.toast('库存不足');
      return;
    }
    emits('buy', state.selectedSku);
	}

	// 改变禁用状态：计算每个 property 属性值的按钮，是否禁用
	function changeDisabled(isChecked = false, propertyId = 0, valueId = 0) {
    let newSkus = []; // 所有可以选择的 sku 数组
		if (isChecked) {
			// 情况一：选中 property
			// 获得当前点击选中 property 的、所有可用 SKU
			for (let price of skuList.value) {
				if (price.stock <= 0) {
					continue;
				}
				if (price.value_id_array.indexOf(valueId) >= 0) {
					newSkus.push(price);
				}
			}
		} else {
			// 情况二：取消选中 property
			// 当前所选 property 下，所有可以选择的 SKU
			newSkus = getCanUseSkuList();
		}

		// 所有存在并且有库存未选择的 SKU 的 value 属性值 id
		let noChooseValueIds = [];
		for (let price of newSkus) {
			noChooseValueIds = noChooseValueIds.concat(price.value_id_array);
		}
		noChooseValueIds = Array.from(new Set(noChooseValueIds)); // 去重

		if (isChecked) {
			// 去除当前选中的 value 属性值 id
			let index = noChooseValueIds.indexOf(valueId);
			noChooseValueIds.splice(index, 1);
		} else {
			// 循环去除当前已选择的 value 属性值 id
			state.currentPropertyArray.forEach((currentPropertyId) => {
				if (currentPropertyId.toString() !== '') {
          return;
				}
        // currentPropertyId 为空是反选 填充的
        let index = noChooseValueIds.indexOf(currentPropertyId);
        if (index >= 0) {
          // currentPropertyId 存在于 noChooseValueIds
          noChooseValueIds.splice(index, 1);
        }
			});
		}

    // 当前已选择的 property 数组
		let choosePropertyIds = [];
		if (!isChecked) {
			// 当前已选择的 property
			state.currentPropertyArray.forEach((currentPropertyId, currentValueId) => {
				if (currentPropertyId !== '') {
					// currentPropertyId 为空是反选 填充的
					choosePropertyIds.push(currentValueId);
				}
			});
		} else {
			// 当前点击选择的 property
			choosePropertyIds = [propertyId];
		}

    for (let propertyIndex in propertyList) {
			// 当前点击的 property、或者取消选择时候，已选中的 property 不进行处理
			if (choosePropertyIds.indexOf(propertyList[propertyIndex]['id']) >= 0) {
				continue;
			}
      // 如果当前 property id 不存在于有库存的 SKU 中，则禁用
      for (let valueIndex in propertyList[propertyIndex]['values']) {
				propertyList[propertyIndex]['values'][valueIndex]['disabled'] =
          noChooseValueIds.indexOf(propertyList[propertyIndex]['values'][valueIndex]['id']) < 0; // true 禁用 or false 不禁用
			}
		}
	}

	// 当前所选属性下，获取所有有库存的 SKU 们
	function getCanUseSkuList() {
		let newSkus = [];
		for (let sku of skuList.value) {
			if (sku.stock <= 0) {
				continue;
			}
      let isOk = true;
      state.currentPropertyArray.forEach((propertyId) => {
				// propertyId 不为空，并且，这个 条 sku 没有被选中，则排除
				if (propertyId.toString() !== '' && sku.value_id_array.indexOf(propertyId) < 0) {
					isOk = false;
				}
			});
			if (isOk) {
				newSkus.push(sku);
			}
		}
		return newSkus;
	}

	// 选择规格
	function onSelectSku(propertyId, valueId) {
		// 清空已选择
		let isChecked = true; // 选中 or 取消选中
		if (state.currentPropertyArray[propertyId] !== undefined && state.currentPropertyArray[propertyId] === valueId) {
			// 点击已被选中的，删除并填充 ''
			isChecked = false;
			state.currentPropertyArray.splice(propertyId, 1, '');
		} else {
			// 选中
			state.currentPropertyArray[propertyId] = valueId;
		}

    // 选中的 property 大类
		let choosePropertyId = [];
		state.currentPropertyArray.forEach((currentPropertyId) => {
			if (currentPropertyId !== '') {
				// currentPropertyId 为空是反选 填充的
				choosePropertyId.push(currentPropertyId);
			}
		});

		// 当前所选 property 下，所有可以选择的 SKU 们
		let newSkuList = getCanUseSkuList();

		// 判断所有 property 大类是否选择完成
		if (choosePropertyId.length === propertyList.length && newSkuList.length) {
			newSkuList[0].goods_num = state.selectedSku.goods_num || 1;
			state.selectedSku = newSkuList[0];
		} else {
			state.selectedSku = {};
		}

		// 改变 property 禁用状态
		changeDisabled(isChecked, propertyId, valueId);
	}

	changeDisabled(false);
  // TODO 芋艿：待讨论的优化点：1）单规格，要不要默认选中；2）默认要不要选中第一个规格
</script>

<style lang="scss" scoped>
	// 购买
	.buy-box {
		padding: 10rpx 0;

		.add-btn {
			width: 356rpx;
			height: 80rpx;
			border-radius: 40rpx 0 0 40rpx;
			background-color: var(--ui-BG-Main-light);
			color: var(--ui-BG-Main);
		}

		.buy-btn {
			width: 356rpx;
			height: 80rpx;
			border-radius: 0 40rpx 40rpx 0;
			background: linear-gradient(90deg, var(--ui-BG-Main), var(--ui-BG-Main-gradient));
			color: #fff;
		}

		.score-btn {
			width: 100%;
			margin: 0 20rpx;
			height: 80rpx;
			border-radius: 40rpx;
			background: linear-gradient(90deg, var(--ui-BG-Main), var(--ui-BG-Main-gradient));
			color: #fff;
		}
	}

	.ss-modal-box {
		border-radius: 30rpx 30rpx 0 0;
		max-height: 1000rpx;

		.modal-header {
			position: relative;
			padding: 80rpx 20rpx 40rpx;

			.sku-image {
				width: 160rpx;
				height: 160rpx;
				border-radius: 10rpx;
			}

			.header-right {
				height: 160rpx;
			}

			.close-icon {
				position: absolute;
				top: 10rpx;
				right: 20rpx;
				font-size: 46rpx;
				opacity: 0.2;
			}

			.goods-title {
				font-size: 28rpx;
				font-weight: 500;
				line-height: 42rpx;
			}

			.score-img {
				width: 36rpx;
				height: 36rpx;
				margin: 0 4rpx;
			}

			.score-text {
				font-size: 30rpx;
				font-weight: 500;
				color: $red;
				font-family: OPPOSANS;
			}

			.price-text {
				font-size: 30rpx;
				font-weight: 500;
				color: $red;
				font-family: OPPOSANS;

				&::before {
					content: '￥';
					font-size: 30rpx;
					font-weight: 500;
					color: $red;
				}
			}

			.stock-text {
				font-size: 26rpx;
				color: #999999;
			}
		}

		.modal-content {
			padding: 0 20rpx;

			.modal-content-scroll {
				max-height: 600rpx;

				.label-text {
					font-size: 26rpx;
					font-weight: 500;
				}

				.buy-num-box {
					height: 100rpx;
				}

				.spec-btn {
					height: 60rpx;
					min-width: 100rpx;
					padding: 0 30rpx;
					background: #f4f4f4;
					border-radius: 30rpx;
					color: #434343;
					font-size: 26rpx;
					margin-right: 10rpx;
					margin-bottom: 10rpx;
				}

				.disabled-btn {
					font-weight: 400;
					color: #c6c6c6;
					background: #f8f8f8;
				}
			}
		}
	}
</style>